1. I solved my Lag problems by ignoring party/clan based game modes.
2. I agree, it must be a bug or something. Hope they fix this soon.
3. Thats because he has a lower ping to Host then you, its not your fault either.
4. Haven't experienced it yet.
Overall i find Black Ops 2 to be the best Call of Duty ever made, no game is ever perfect but this game is near close to being perfect. No noob tubes, no commando, no ghost campers, no assassin campers, no op killstreaks, no op perks. Love it.
This game would be great if......3arc didn't leave the hardcore community on that deserted island of reject toys from Rudolf the Red Nose Reindeer. Good game, ghost is really dumb cause you have to be in full sprint for it to work.